A few Trilobite Fossil Groups in the BAS in Arizona

[Arizona Chris]

HI all,

 

As we work through the thousands of slabs of Bright Angel shale from the last few expeditions, I thought Id post for fun some of the more fossil packed slabs we pulled out of the outcrop.  Trilobites overlapping trilobites!  They are all one dominant type - Zacanthoides Walapai, and are typically molts.  Trilobites are not common here in Arizona, but if you get into the right layers....

 

http://www.schursastrophotography.com/paleo/Fossilfotos-4b.html

 

Arizona Chris

Paleo Web site:  http://www.schursastrophotography.com/fossiladventures.html

[Miocene_Mason]

Wow, I didn't know trilobites could ever be found like that! Nice finds!

[Arizona Chris]

Not normally here in Arizona anyway.  Most of the time we find single pygidiums or glabellas on huge boulders that you cant move.  However, we did find another site in the BAS in northern Arizona which the limestone is actually MADE of trilobite hash.  In another site near Tombstone (yes - the famous OK corral town) there is a hill of Abrigo cambrian limestone that is so packed with trilobites that it looks like cottage cheese!  Oh My.

 

Arizona Chris

[Wrangellian]

It is nice to know some of that Lower Paleozoic (Cambrian) stuff in that area isn't only exposed in the no-collecting Grand Canyon.

[Arizona Chris]

Yes that is true!  The depths of the Canyon however are a great place to photograph the cambrian trace fossils.  Along the route to Plateau Point, the tapeats boulders they line the trail with are packed with trilobite trackways - Cruzianna and Rusophycus resting traces.  

 

Arizona Chris

[Wrangellian]

Any pics of those?

It's too bad so many of the best fossil sites are in designated no-collecting areas like parks. Restrictions are fine if collecting was going to ruin something else of higher value or make things unsafe, or if the fossils/traces are better appreciated in situ (and something is done to protect them from erosion), but otherwise it's a colossal waste! (At least experienced collectors should be allowed to collect for museums/science, if not Joe Public bashing them out and losing the information before selling them on ebay..)

[Arizona Chris]

Yeah, I found a great slab along the Tonto trail that connects the two main trails in the South Rim along Pipe Creek.  It is 6 feet square, a foot thick and covered with hundreds of six foot caruzianna trackways like a huge tic-tac-toe board.  Wouldnt that one ton slab look great in my front yard!

[Wrangellian]

I bet it would...